Helicobacter pylori (H. pylori) is a spiral shaped bacterium
that lives in or on the lining of the stomach. It causes more than 90 percent
of ulcers, which are sores in the lining of the stomach or the duodenum (the
first part of the small intestine). Before 1982, when this bacterium was
discovered, spicy food, acid, stress and lifestyle were considered the major
causes of ulcers. Since it is now known that most ulcers are caused by an
infection with H. pylori, they can be cured with appropriate
antibiotics.

How common is H. pylori?

About two-thirds of the world's population is infected with H.
pylori. In the United States, H. pylori is found more often in older
adults, African Americans, Hispanics and lower socioeconomic groups.

What illness can H. pylori cause?

Most persons who are infected with H. pylori never have any symptoms
or problems related to this infection; however, H. pylori can cause
gastritis (inflammation of the lining of the stomach) or ulcers of the stomach
or duodenum. About 25 million Americans suffer from ulcers.

What are the symptoms of ulcers?

The most common ulcer symptom is gnawing or burning pain in the abdomen
between the breastbone and the navel. Commonly, the pain occurs when the
stomach is empty  between meals and in the early morning hours  but
it also can occur at other times of the day. It may last from minutes to hours
and may be relieved by eating or taking antacids. Less common symptoms include
nausea, vomiting and loss of appetite. Sometimes ulcers may bleed; if bleeding
continues for a long time, it may lead to anemia with weakness and fatigue. If
bleeding is heavy, blood may appear in vomit or stool. Stool containing blood
may appear tarry or black.

How is the infection diagnosed?

Physicians have several methods to test for H. pylori infection.
Blood tests can determine if a person has been infected by measuring specific
H. pylori antibodies. A breath test can determine if H. pylori is
in the patient's stomach. In this test, the patient is given a harmless
substance  urea with carbon  to drink. H. pylori breaks down
this urea, and the carbon is absorbed into the bloodstream and lungs and then
exhaled in the breath. By collecting this breath, the health care provider can
measure the carbon and determine whether the bacteria are present.

A physician also can perform endoscopy, in which a small flexible instrument
with a camera inside is inserted through the mouth into the esophagus, stomach
and duodenum to look for ulcers. During endoscopy, biopsy specimens (tissue
samples) of the stomach lining can be obtained. Several tests can be performed
on these tissue samples to determine if the patient is infected with H.
pylori.

Should H. pylori be treated?

Persons with stomach or duodenal ulcers should be tested for H.
pylori and, if found to be infected, be treated with an antibiotic.
Antibiotics are the new cure for ulcers; therapy consists of one to two weeks
of one or two antibiotics and a medicine that will reduce the acid in the
stomach. This treatment is a dramatic medical advance because eliminating H.
pylori with antibiotics means that there is a greater than 90 percent
chance the ulcer can be cured for good.

How do people get infected with H. pylori?

It is not known how the bacteria get into the body or why some people with
H. pylori become ill while others do not. The bacteria most likely
spread from person to person through the fecal-oral route (when infected fecal
matter comes in contact with hands, food or water) or the oral-oral route (when
infected saliva or vomit comes in contact with hands, food or water).

What can people do to prevent infection?

Since the source of H. pylori is not yet known, recommendations for
avoiding infection have not been made. In general, it is always wise to eat
food that has been properly prepared and to drink water from a source that is
known to be clean and safe.

Are there any long-term consequences of H. pylori infection?

Recent studies have shown an association between long-term infection with
H. pylori and the development of gastric (stomach) cancer. Gastric
cancer is the second most common cancer worldwide; it is most common in
countries such as Colombia and China, where H. pylori infects more than
half the population in early childhood. In the United States, where H.
pylori is less common in young people, gastric cancer rates have decreased
since the 1930s.

How can I learn more about H. pylori?

Consult your physician if you are concerned about H. pylori. Although
knowledge about the bacteria is incomplete, scientists are working to find out
how persons become infected, why some people develop symptoms and what the best
treatments are.

(This HealthBeat was adapted from a fact sheet developed by the U.S.
Centers for Disease Control and Prevention.)